---
id: CVE-2026-39838
title: >-
  Improper neutralization of input during web page generation ('cross-site
  scripting') vulnerability in Wikimedia Foundation MediaWiki - ProofreadPage
  Extension allows XSS Targeting Non-Script Elements.

  The issue has been remediated on the…
summary: >-
  Improper neutralization of input during web page generation ('cross-site
  scripting') vulnerability in Wikimedia Foundation MediaWiki - ProofreadPage
  Extension allows XSS Targeting Non-Script Elements.

  The issue has been remediated on the…
severity: none
cwe:
  - CWE-79
published: '2026-04-07'
updated: '2026-07-21'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-39838'
references:
  - url: 'https://gerrit.wikimedia.org/r/q/Idd51e18479b32b7176b43ff74ca1c49d6bdd0628'
    label: c4f26cc8-17ff-4c99-b5e2-38fc1793eacc
  - url: 'https://phabricator.wikimedia.org/T406088'
    label: c4f26cc8-17ff-4c99-b5e2-38fc1793eacc
tags:
  - nvd
epss: 0.00453
epssPercentile: 0.36745
ingestedAt: '2026-07-22T07:59:32.375Z'
---

## Overview

Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Wikimedia Foundation MediaWiki - ProofreadPage Extension allows XSS Targeting Non-Script Elements.
The issue has been remediated on the `master` branch, and in the release branches for MediaWiki versions 1.43, 1.44, and 1.45.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.